Not all monitors are as good as the next. You will need to do your research! Consider what range or distance you will require, will you need sensor pads to alert you if baby stops breathing and do you really want video to see what they are up to? It is worth doing some reading, checking out some blogs and asking a few friends. We have found the Angelcare monitors to be reliable, and we also notice that Apple have a couple of monitors out which connect with your iPhone & iPad! If you have used one of these perhaps you could send us some feedback!
Investing in a good cot which will last you for many years can actually save you money in the long run. Consider a cot which transforms into a toddler bed could be a good option for you. We love Leander, their cot caters for newborn through to junior!