[pilleya]

The decision between Mini-CIM and 775pro really comes down to two factors weight and cost.

The tight budget that you are on might mean that it might be better to go for the Mini-CIM's, the difference in weight is significant, but shouldn't be a problem if you plan for the weight of your robot. Also while VersaPlanetaries are reasonably expensive, the are very customisable so they can be reused season after season( providing that they are cared for).