Welcome Peter. The market is very lacking in used Eribas at the moment, but your budget should get you a good example once things settle down. I would not rush into buying as the season is now nearing the end so you have time on your side.
I’m guessing you will be sleeping across the van to get max bed length so you want to look for a 2.1m wide Troll. Any 550, 552, 555 will do. If it is a 530 or 540 then you will need a post 2010 van.
Colin