You're not crazy.
Find out from Apria what it will cost for the machine before you sign any dotted line.
Add up your monthly costs out-of-pocket. Remember to include what the cost will be when the year rolls over and your deductible starts over - because it will. Many times, you will find that your out-of-pocket cost through Apria will be more expensive than if you had just bought it straight form cpap.com at their cost. Similarly with masks, straps, hoses, etc. Make a spreadsheet to be sure you don't pay more than you need to. CPAP.com also accepts BCBS through 'billmyinsurance.com'.
Some of us have had bad experiences with some DME's. Apria is not among the favorite of a number of users here, but there are reports of good interaction for some Apria centers in some cities.
Make sure the doc prescribes an auto, regardless of whether it's a cpap or a bipap.
From my point of view, lab titration is often lower than what your eventual titration should actually be, probably because your body gets used to using the machine, changes in pharmaceutical prescriptions, sleep patterns, sleeping in a familiar environment, etc. This has been called
titration creep. Once you're in your home with the machine and you have a pressure that works for you on auto, you can set the machine as a straight cpap (or bipap) at your preferred pressure regime. I think all autos are data capable, so be sure to get the software that goes with your machine. This is better than having to go back the the doc for yet another sleep lab when they find out that oh, yeah, your titration was too low. It's also a lot less expensive in the long run.