IMHO....If you are considering buying a bike you think you are going to upgrade soon after getting it, then look harder for a model with what you want. And up the budget by what your upgrade will cost including tools and time spent.

For gearing, you need to consider what you have now, what ratios you use the most and what extremes do you occasionally need. Then find an online gear calculator and compare ratios and gain. I frequently use https://www.bikecalc.com/gear_ratios I does what I want, so I've not looked around to see if any others present the info better. A con is since you only put in the min/max sizes, you get a lot of info for gears you don't have. However a pro for that site is that it's quick to set up for the same reason as it's con, you only have to enter min/max gears.