Assuming the rest of your gelcoat is either in good shape, or can be brought back (compounding or buffing) - and that you like the color - repairing a small area of it will probably be much less work and expense than painting
Prepping for paint
and then doing a good paint
job is no small feat. It is a lot of work to do it right, and supplies are expensive. Especially if you use a premium coating, like a two-part LPU (more durable and the gloss is much longer lasting than a one-part paint
such as Interlux Brightsides, which is a modified alkyd paint).
Now, that's not to say you shouldn't paint. A good paint job is a wonderful thing. Some high-end boatbuilders are delivering new boats with LPU paint instead of gelcoat right from the get-go. But making a gelcoat repair is going to be much easier and more cost effective, if it is feasible.
(And if you decide to go ahead with a repair we can give you tips.)