Could I just use a tank designed for fish instead of reptiles?

[Homebody]

I'm upgrading my snake's tank, and I'm currently looking at different places near me that have different size tanks and what the prices are. Could I just get a fish tank instead of a reptile tank? A 40 gallon aquarium is 55 bucks, versus a 40 gallon reptile tank is 130. Would it be bad if I just got an aquarium instead? Of course I'd have to get a top as well, but still.

It's tough to adapt something that is not a reptile enclosure into a reptile enclosure and save money. It takes time, skill, tools and materials to do so, and that costs money. In the end, you may very well end up with an enclosure that doesn't look as nice, work as well, and costs more. So, don't compare the cost of the reptile enclosure to the fish tank. Compare the cost of the reptile enclosure to the fish tank plus all you'll need to adapt it. If you're handy, you have access tools and cheap materials, you may be able to make it work. If not, I think the reptile enclosure is the better deal.