True the best thing for them is a large base rather than the water volume being made up from height. Some like to take the odd gulp from the surface so obviously the less they have to travel the better. Some species do it more than others. However, they do this as a coping mechanism from the wild when oxygen levels drop, so as long as you have excellent circulation and good oxygen uptake in the tank, it shouldn't be a problem. Ny tank is about 40cm high. The only cory which gulps is my big albino female, she's done it in every tank she's been in. It's rare any of the others do it, except maybe in the height of summer.
Fishkeeping and budgets don't go do they? Believe me I know! It's up to you, depending on how kind Santa is, but personally I wouldn't pay £140 for a tank under 100 litres. I would keep an eye out for a good second hand deal. They DO pop up. I live in a small town and there is a fluval 200 litre tank and stand on eBay near me for just over £100. If I had room...!