98 s90 stuck in 2nd gear

[missa27nh]

So this is the problem we have been having.. sometimes it runs fine most times it doesn't go past 2nd gear which we were told is pretty much a safe mode due to a bad shift solenoid.. I myself am not mechanically inclined nor is my husband. We were quoted 500$ to fix but now are being told parts for my car are expensive and rare.. is there anything else other then the solenoid that could be causing this? the arrow goes on the s w e lights flash other then that I can't think of anything else it does.. please help thank you