It is impossible to give an opinion without pictures...but there is much more to worry about with a sunk hull than merely the hole repair. Done correctly, holes in hulls can be repaired to be even stronger than original unless there is structural damage beyond a simple hole.
Other possibilities that may result from a sinking...keel/hull joint damage, deck saturation with core rot, engine destruction, wiring destruction, bulkhead integrity compromised, etc. etc.
The price needs to be VERY attractive to even consider such a boat and then ONLY with the advice of a very competent surveyor. You can easily own a cheap boat that will cost you FAR more to repair than the same boat in good condition on the marketplace.
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