No matter how much money you have to spend though you should be able to find something in your price range. If you have cash to work with, you may be able to get the seller to lower the price too. When they see the cash in hand for what they are selling, it can be a huge incentive.
For now, you will have to create a livable vehicle that has the needs covered. It may not be the most comfortable though and you may have to go without many perks for now. Make a list of your items that you want and those that you need. Separate them and then as you have money to invest, you can continue to add items from your want list to the vehicle.