Reply to Incorporating MP3 to current Vinyl Setup

First post here hoping to get some advice on how I can incorporate mixing MP3's with my current setup

I am currently using the following

Pioneer DJM-850
2 Technics 1200's

I love vinyl but purchasing and mixing vinyl only is not affordable for me right now and I would like to start mixing MP3's. I would want to use MP3's in my sets while still using vinyl of course. What would you guys recommend me using to make this happen. Not entirely sure I can use Traktor and the 1200's timecoded vinyls while still using the vinyls I already have. The cheapest option would be best until I have enough for a CDJ that allows me to use USB. I'm believeing a CDJ is the only option but I am not overly familiar with some of the software available now so I may be wrong.

Thanks in advance for any suggestions.