There's nothing wrong with experiencing diving with a resort course, so long as it's properly conducted. There should be two separate sessions in the water, the first in a pool or similar environment, the second in shallow open water. The first should start in water you can stand in, and progress to rather deeper water. Though if you're progressing beyond getting an "experience" then there's not much point.

However, there is a way of structuring the certification course so that it's modular and you can stop at either of two intermediate points instead of proceeding all the way to Open Water - after the first half day at the Resort Course stage, or after two days at the Scuba Diver stage (this lower certification level is only offered by PADI, and most other agencies don't agree with it). There is no reason why the overall cost should be any more than the regular cost for the final level achieved, whichever of the three stages that is. So long as the training is so structured, that is - if you simply do a resort course and later decide to do a certification course you'll pay for each level.

Hol Chan is a tricky place to do a starter-level course because of the unpredictable currents, and I generally choose not to go there. I prefer somewhere where even if there is a current it isn't such a factor.