Bennington makes 2 main full length tritoon hulls. I believe you’ll have the SPS on that boat, but wouldn‘t hurt to verify (The other one is the ESP tritoon hull). Should have under-skinning, but again verify.
Since it is a XP version of the 2017 S-series, that was the Premium package, it has a lot of mainly interior aethetic upgrades (furniture, kick board and flooring areas, helm and captains seat, stitching, etc). The SSR would not have been a new model or layout that year, but upgrading the vinyl seating to the current Semtex fabric as part of the S-XP model was new in the S-premium that year.
Bennington got rid of that XP premium designation around 2020-21 when they created the L series model lineup. Thus, if you bought the SAME Bennington configuration today, it would be a 22 LSR.
Do the sellers have its original spec purchase sheet for you to look over? You could spec up that version of the boat today to see today’s cost. It’ll likely make you feel better about whatever this seller is asking (ha!) since prices of increased significantly every year since 2017. Average price off MSRP back in 2017 when buying from a dealership on the s-series was around 20% off MSRP (some got more, some got less depending on a ton of factors at that time).
Boats of this time period (I have a 2017 SSBXP SPS hull 200 Mercury Verado pro and am thus highly dialed into some of what you are looking at now) have often been selling basically for what the person bought them for new if in good shape. GOOD pre-owned boats have really held their value well! The year over year increase in new boat prices have really supported strong used boat prices since 2016-17.
I’d say if it is near original purchase price or less, it’s probably going to be a fair price. But I don’t know for sure, or how increased interest rates the last 8-10 months have impacted the used boat market.
Otherwise, there is a WIDE range of options and upgrades. Kind of hard to pin down ”what to look for” as it can be very unique to each buyer. This also creates challenges in trying to NADA/KBB your boats value. Those tools don‘t factor in well the value of options, and the low supply, high demand that these boats have been commanding in resale price. Trying to compare it to similarly spec’d 22’ 2017 SXP Bennington’s with 150 HP motors on them is your best bet, even if the floor plan is different.
Areas where people may spend a lot, or save a lot, is in LED lighting and stereo system options. You could try to figure out what, if any, of those options they added to the boat. Those options at least add a lot to original price, and often contribute to helping bolster resale price.
My wife and I: in addition to what the premium package, blackout package and SPS hull package came with that year (again, we have all those on our 2017), I wanted the Simrad gps/depth finder, upgraded Kicker stereo and speakers, RGB LED lighting options (speakers, under-seating, rear seating, external pontoons), dual battery & perko switch, port gate seat, our specific flooring, power electric curved bimini, and traditional ladder.
What we didn’t add on, but is not uncommon to have, is the privacy curtain and/or porta-potty options selected too. And of course there were a lot of other options back in 2017 one could have gotten.