Really just echoing what manX and others have said > get the best guitar you can afford and aguitar that wants you to play it. Wanting to play guitar is three things; physical, ergonomic and emotional.

Physical and ergonomic are kinda the same thing but I differentiate between the two a bit.

Ergonomics is really a matter of (oversimplified) of whether or not the guitar seems confortable to play. Is it good when you sit to practice? Does feel right when you're standing while strapped? Do you feel like playing it seems comfy or does the instrument seem like it's fighting you? You want to be sure that the guitar you play does not seem like a strain to do so. If it did, you stop enjoying it.

What's physical, then? Similar (very) to ergonomics, it's a matter of how the instrument feels when you play. Physical also bleeds in to emotional a bit. When you play, you're doing a physical task and it has to feel like you're playing the instrument. You are (eventually) in command. That you are playing the guitar and the guitar is not playing you. Like your current guitar, with its challenges, the guitar is playing you. It's telling you what it is capable of doing. On anice playing guitar that you enjoy, you are more able to tell the guitar what you're playing. It seems like an abstraction in a way but I've been playing since the early 80's and every guitar I've purchased has to meet this criteria of my being in command of the instrument.

Emotional? Though it explains itself, when you want to play a guitar, you will play a guitar. It's not just the physical and ergonomics that play in to this role (thought they are very important) but that even when you're sitting across the room and looking at the guitar, you saying 'Yep, just pick up. Even for a few chords." That means that the look, feel and vibe of the guitar matter.

This is all food for thought and only adding to others but it's info that I've used when considering guitars I've owned (or now own...). I personally think it is usewful to get the best guitar you can reasonably afford. If the bedget is limited, there is still an enormous number of guitars that play great and at really affordable prices.

Also, don't worry about callouses, just playing hardens up your fingers not matter electric or acoustic. Just get something you want to play.