ahhh you'll do fine Garz... how old is your son? This is going to be a fantastic journey you both will enjoy.. it will seem like forever doing it, but when you are finished, it will feel like only yesterday when you started.
The wife and I call ours the snowball, for every dollar we spend, it requires another dollar. And when you are faced with blowing $300 but the rest of the world tells you they got theirs for less than two, just smile and tell yourself how lucky you are to have these problems.
Congrats and good luck! The best is yet to come...
ps... tell the wife you are doing it all for her... and try to act that way every once in a while too.