I have a 208 with the SX150. As far as I know, I don't have any major issues with the transom. I do every few seasons, scrape out old loose caulking around the cap and the end pieces and reapply marine caulk like Life Seal.
Back when I got he boat in 2006 I had looked at a few boats including 208s and paid my share of survey fees
Some had major moisture issues. A survey is recommended.
The bilge on the 208 is very dry although some water will pool towards the bow. It does not drain aft unless the bow is quite a bit higher than the stern as is the case when launching/hauling on a ramp.
I have replaced a few parts over the years, hinges, latches, fixtures, pumps ( several times) and the like. My boat has all the same 'issues' as other 208s. Nothing major.
If you are going to check out the boat in detail, try to have the motor cold when you start it. See how is starts and sounds when cold, compared to after warm up. Check the trim and tilt pumps and cylinders for signs of leakage or corrosion. The trim mechanism is super expensive to replace assuming you can find one.
A mechanical inspection and a compression test are advised if you are serious about the boat.
Do not forget to factor in the cost to replace things like cushions and canvas if those are shot.
My standard advice is that the general appearance of the boat tells you a lot about the previous owner. If you see big signs of neglect for the cabin, deck and helm, you can be pretty sure the mechanicals were also neglected. On the other hand if a 21 year old boat looks brand new, that raise a red flag for me.
Good luck