I recommend they at least change the oil filter every 3K miles
I wasn't aware that is was even possible to just change the Oil Filter
without also changing the oil, since the Oil Filter
fills itself with the current oil from your engine.
Unless you mean; drain the oil, change the filter, then pour that old oil
you just drained from your engine back in to your engine via the top oil cap.
I would not recommend doing that.
If you cannot spare $20-$35 for 4qts of new oil, how can you spare the cost of a tank of gasoline after driving around for a few days? Maybe shouldn't drive?