As a native of York County (Rock Hill), I have seen Fort Mill grow at astounding rates. I personally attempted to purchase a home in Baxter in 1997. I did not like the "closeness" of the homes, not enough privacy, etc for my taste. Therefore, I purchased NEW construction in Rock Hill, in the country on almost 2 acres of land. The re-sell value of the homes in Baxter are well over the $200-$250K mark now. I had my property appraised in April and it had increased approximately $50K in 10 years. The market in Baxter had appreciated over $100K in 10 years. Thats just my own experience as a "consumer".
As a REALTOR, I would tell you that Fort Mill would be your better option-its still close to Charlotte, BUT the property TAXES are MUCH lower in York County and SC in general than they are in NC.
If I can be of service to you when searching in Fort Mill, I would be honored to show you around the area.
Kimberly Gaffney email@example.com