Hello and
If you love 30-A as much as most of us do, and see yourself there in the long term, either as as secondhomeowner or permanent resident, and you find a piece of property at a great price that you can reasonably afford to purchase that you know you will hang on to, then jump on it! I think putting your current home on the rental market is an excellent way to increase income to make it happen.
However, a few words of caution:
1) Should a hurricane come and wipe out your home, God forbid, make sure you can stretch enough to afford the costs of both places for awhile because no house (or damaged house)=no cash flow.
2) Step back and take an unbiased look at the rental potential of your home. It sounds like with a 2BR 2BA place south of 30-A, you probably have a very good market, but do you have a view? Access to a private or community pool? Both are very important to renters.
3) Search the forums for others' management company experiences and steel yourself for the hassles and challenges of opening your home up to others. If you have special items you are really attached to in your beach home, consider removing them to save your sanity. Rather than just handing your keys to a management company, consider ways to market your property yourself and/or take on some of the workload to reduce commissions.
All in all, it sounds like a sound strategy if you can take all these things into consideration and know you can live with your decision. I wish you lots of luck!