Fixer upper in Hawthorne/Mount Pleasant? (homes, neighborhoods, purchasing)

[r2dc]

We are considering Hawthorne/Mount Pleasant for a single family home with a total budget of $750,000-800,000. We know we are going to need to make modifications to the home to make it wheelchair accessible so we are thinking about purchasing a fixer-upper in the $500,000 range and renovating/possibly even adding square footage to meet our needs rather than paying the price for someone else's renovations. Any thoughts on whether this community would support this in terms of return (i.e. are there neighborhoods of mixed value homes where people are expanding or updating their homes and selling for good return?).

Also does anyone have any idea about average cost per square foot for additions? Are building permits easy to come by?

Thanks in advance!