Hi Stephan,
I think that's a little expensive for an older Searider. ( I also think that Sea riders are the absolute best small boat) if you drop a few pounds pounds and it's in Holland then it's a bargain.
The hull and tubes are very tough on a Searider so unless they are visibly damaged then they are probably sound. If the bottom is antifouled it may be hiding a repair. Electronics fail after a while so they don't count for a large part of the value of the boat. It will probably need a rewire but that's just age.
The engine counts for a good part of the value of the boat and 90 Yamaha's are the best small 2 strokes made, or at least that's what I think. Buy te engine as if you are buying a car. service history, overall condition and get a proper Yamaha expert to check it out. Remember that most sea riders were bought as working boats and as such they would have had a hard life and the engine will have some hours on it
I love Seariders and I am really looking forward to getting mine in the water.
A lot of cloggies do buy there boats over here and they say that the only place where there are enough choices to make a buying trip worthwhile is on the South coast. Southampton + 50 mile radius.
If you want to come over and need somewhere to stay you are welcome to stay with the Jackeens!

(or if you have a sense of humour you can stay with us!)
Send a couple of Digipicks
regards Stuart