First of all budget is countable, and since you've written 'a lot of', then there should be an 's' on budget. But there's another problem. Budget has 2 meanings that are potentially useful in this situation:
Budget as a sum of money that has been set aside for a particular purpose:
Budget as a document containing a list of items:
In both of these examples..
Often students who are preparing for IELTS feel they have to do everything to avoid repetition, and so they use budget instead of money. However, budget is not synonymous with money. When you're talking about money and comparing how much things cost, it's safer to use words like money, cheap, expensive, etc.