Seiko Prospex 62MAS Modern Diver SPB143 (intl ref , see sbdc101) (SPB143, SPB143J1, 62MAS modern). Current Prices, JDM Listings, Market Analysis
The Seiko Prospex 62MAS Modern Diver SPB143 is a reinterpretation of Seiko's original 1965 professional diver, released in 2020 and sold internationally under the SBDC101 reference. The SPB143J1 designation marks the JDM variant, which surfaces regularly in the Japanese secondary market and draws attention from buyers looking to close the gap between US retail and Japan pricing. Tonbo tracks this model because it sits in an active price band where arbitrage opportunities can appear, and because the JDM-versus-international distinction creates real buying decisions. At a US median of $850, the SPB143 price sits comfortably within reach of serious watch buyers while still leaving room for a favorable purchase.
Current US Market Value
Based on 75 verified sales, the Seiko Prospex 62MAS Modern Diver SPB143 (intl ref , see sbdc101) SPB143 carries a current US median of $850. The interquartile range runs from $705 at the 25th percentile to $991 at the 75th percentile, which is a reasonably tight spread for a current-production diver and suggests consistent demand without dramatic condition-driven outliers at the top end. Comp quality is rated 🟢 Verified, meaning these figures come from confirmed sold listings rather than ask prices. A sample size of 75 is sufficient to treat the median as reliable, though the watch remains in production, so new supply continues to anchor the ceiling.
Active JDM Listings
Japan-side activity has been light over the past two weeks, with one confirmed listing appearing on the Japanese market in late May. That single data point limits what can be concluded about current Japanese supply, but it is not unusual for JDM models at this price tier to move quickly when priced attractively. Buyers monitoring Japan for a deal on SPB143 for sale should set persistent alerts rather than check manually.
- May 25 listing appeared on the Japanese platform at ¥939, though condition details were not specified in the available data
- The ¥939 figure is notably low and warrants careful condition verification before drawing conclusions about Japanese market pricing broadly
- JDM supply at this model's price point tends to be episodic rather than continuous
- The SPB143J1 variant specifically may carry slight premiums or discounts versus the international SBDC101 depending on the seller's market awareness
- No additional active Japanese listings were recorded in the past 14 days beyond the single May 25 entry
Recent Alert History
No strict or opportunity alerts have fired for the SPB143 in the past 90 days. This does not mean the model is a poor tracking target. It means no listed price has cleared the thresholds Tonbo uses to flag actionable deals during that window. For a current-production watch with a verified comp base, the absence of alerts is a normal state. The market has been trading within its established band rather than producing the outlier pricing that triggers a signal. When pricing does break below the established range, the alert system at tonbomarket.com/signals will flag it immediately.
Japan vs. US Price Gap
The primary driver of any US-Japan price gap on the SPB143 is the JDM channel itself. Japanese sellers often price for a domestic audience with different reference points, and the SPB143J1 variant does not always get the same visibility on international platforms that the SBDC101 reference does, which can create mispricing opportunities for buyers who know both references refer to substantially the same watch. Import costs, shipping, and customs duties need to be factored against the spread before assuming a Japanese purchase outperforms buying domestically. The main risk here is the current-production status of this model. Unlike discontinued references where supply is fixed, the SPB143 can always be purchased new, which keeps a soft ceiling on what the secondary market will bear and limits how aggressively prices can run. Condition variance is the secondary risk, particularly for listings where grading is vague or photos are limited. Check the deals tracker for SPB143 listings that have been reviewed for condition notes.
Get Real-Time Alerts for Seiko Prospex 62MAS Modern Diver SPB143 (intl ref , see sbdc101)
If you are watching the SPB143 price and want to buy SPB143 Japan at the right moment, the most practical step is setting a price alert rather than checking manually. Tonbo's alert system monitors Japanese and US secondary markets continuously and flags listings that fall outside normal range. Pricing data and alert tiers are available at tonbomarket.com/pricing. For a broader view of JDM market movements without a subscription commitment, the free newsletter at tonbomarket.com covers notable deals and market shifts across tracked Seiko references on a regular cadence.