If this is your first meter, I wouldn't worry about it.
I find that anytime I care enough about a signal to need true RMS, I need an oscilloscope anyway...
If you are in the market for a cheap meter, one of the forum members here has an ebay store out of hong kong:
http://stores.ebay.com/99centhobbiesTake at look at the UNI-T UT61-E (which is true RMS, and has serial out), or the (cheaper) Digitek DT-4000ZC (which has serial out, but is not true RMS).