Private investagators do it all the time, and most of them don't have anymore resources then you.
You'd be surprised. Private investigators are expensive to hire - they'll have better equipment than you, probably. If they're serious about following a target, it won't be one investigator doing that, but a group of investigators - so, manpower resources. Finally, most jurisdictions require a license for private investigators, which would make their actions legal, unlike you if you were following someone.