LapTopNav is just SeaClear, NOAA charts, and a USB GPS receiver. SeaClear is free. As in, costs absolutely nothing. NOAA charts, too. Download them anytime you want, completely free. So what you are paying $99 for is the USB GPS. You can buy a USB GPS off of E-Bay, or Amazon for less than $40.
Some people don't want to take the time to download the software and charts for themselves, and so they think this kind of deal is worth it. Okay, maybe so. On the other hand, what are they going to do when it comes time to update the charts (which will happen soon) or the software (which will happen eventually)? Are they going to spend the money to buy the CD again!?!
My advice is to forget LapTopNav, download some charts from NOAA (find them here... Nautical Charts & Pubs
), then download BOTH SeaClear and OpenCPN and try them out. Decide which one you like and uninstall the other.
Now all you need is a way to feed a GPS signal to the PC. Do you still have that GPS you got from Delorme? It will probably work just fine. Give it a try. If not, buy yourself a new USB GPS from Amazon for $30-$40 and you'll be all set.