Regardless of what you want to do with your web site, how much would you spend on your very first one? Remember that you are new to the game and may not know all you need to in terms of owning, maintaining and running a web site for profit.
When first starting out I try and spend as little as possible and only use the money I make from the site to then further the sites expansion. I do this because if for some reason the site doesn't turn out how I wanted it too, it means I either don't lose anything or only money the site itself generated and nothing straight out of my pocket. I'll usually set the site up on free hosting to begin with and find a discount code and get a domain for $1.00 then work from there. I might throw in some lose change here and there to give it a little boost but nothing too much.
As little as possible. I would say to opt for free alternatives at first then move to higher quality options when your websites grow enough to give you a positive monthly balance.