. Are these between the chambers internaly?
I guess that if you haven't a leak on the tubes then it'll probably be OK but it is preferable to have indipendant chambers (safety resons).
$2200 is very cheap....What's the outboard like? It's an older Suzuki but the outside looks very clean.
If it was me, I'd buy the boat subject to engine and boat state. Use it as experience for close shore type cruising, keeping an eye on the RIB market. I'm sure that with a little effort DIY you could increase your investment and if the worst happened and the boat let you down you'd get pretty much what you paid for the outfit from just selling the outboard.
Make him an offer, he seems desparate to sell it! Offer him $1500...
It's your choice though!