Occupancy has a strict definition and a loose market one, and your ten point spread is almost certainly that. Strictly, occupancy is booked nights divided by nights the listing was available on the calendar, so owner blocks and off-season closures come out of the denominator. Loosely, plenty of sources publish booked nights divided by all 365, which drags the number down and is closer to what your bank account experiences. Whenever someone quotes you a figure, ask which denominator, and use the 365 version for underwriting since the mortgage is due in February too.
The stack itself, with the caveat that vendor pricing moves and you should check current rates directly:
Dynamic pricing tools generally charge either around 1% of booked revenue or a flat fee in the $20 per listing per month range. At two listings the flat plans usually win.
A property management system matters when you're on more than one booking channel and need one calendar. Several charge nothing under a handful of listings, others run $10 to $40 per listing per month. At two listings on a single platform you can skip it for a while.
Smart lock, $150 to $300 per door installed, one time, plus batteries you will forget. Noise monitoring devices run $100 to $200 per unit with a subscription around $100 a year. Market data subscriptions sit anywhere from $20 to $100 a month depending on depth.
Cleaning is the big one and it isn't software: $80 to $150 per turn in most markets, normally billed to the guest, though short stays and last minute turns are where the guest fee stops covering the invoice. Budget a few dollars per stay for consumables and a linen replacement line, since towels wear out on a schedule nobody models.