I had my hair cut and coloured on a whim a few years back. I wasn't lucky enough to be able to tie it up it was so short, and combined with my glasses I managed to look like Valma from Scooby Doo (not the look I was going for)!
At the time I was quoted around $600 for extensions, can't recall any details. This was well out of my price range, so I ended up going to Hairhouse warehouse where I bought a fake one piece extension for $40. Next time I went to hair dresser I got them to match the colour. Nobody ever realised I was wearing the piece, and seeing as I change the colour of my hair often, I now have a collection of clip-in extensions of different types. Some are real hair and ten piece sets, however the fake one piece remains my favourite.
Could this be an option for you until your hair gets a bit longer?