Which custom field to use for channel fees?

My rental agreement is currently not showing the full amount guests pay to VRBO, it is missing the channel fees and taxes collected by VRBO.

I use these fields in my agreement

TOTAL UNIT FEE:  {BTAMT}       
SECURITY DEPOSIT:   {BSDAMT}

I suspect that {BTAMT} used to include channel fees but it seems like it no longer does...

(example from VRBO - I want the total traveler payment amount, not just Booking amount)

4 nights $2,816.00
Administrative Fee $80.00
Cleaning Fee $110.00
==> Booking amount $3,006.00

Refundable damage deposit$100.00
Lodging taxes we remit $138.26
Traveler service fee $286.00
==> Total traveler payment $3,524.26

Not my business but WHY would you include the fees that renters pay to VRBO, not you. that would imply that you are somehow responsible for those. IMO you should ONLY show what renters pay YOU. What they pay to vrbo is between them and VRBO.
There are 2 contracts going on:
One between renter and VRBO ( they pay service fee to vrbo for privilege of using vrbo's site)
One between renter and you (they pay you for privilege to stay in your house).

you are not a party to the 1st one. I'd leave it out. taxes ma be a different story depending on who remits them.

It's a fair question - I recently had a guest ask me why the amount listed in the rental agreement was different from what VRBO says is their total, and it took me time to draft a response. I think the guest was wondering if I was doing something sneaky.

I know that if I was the guest signing the RA I would double check that the amount I see in the agreement against what I paid. And since those amounts differ I'd have to wonder whether a mistake was made.... So I'm just thinking by listing the full payment made to VRBO and the lesser amount paid to me is a safe thing that can avoid anyone having the same thought process.

Here is how I solve it. Manual but works. I created a "booking" custom field {BXSVCFEE} for the fee. When a booking gets imported into OR, the service fee is shown there. I manually populate the custom field with that amount. The way I use the field is post departure they get review request email and it says " did you know that if you booked direct , you could have saved $X" where $x is the amount of the fee.

Dear {CFIRST},

If you can take a couple of minutes out of your busy day, we'd appreciate it if you would fill an online review of your choice so that other guests can see what to expect. 

Review on our website <link>

Review on Google <link>

Did you know that 3rd party site such as {BSOURCE} that you used to  book our cabin mark up our rate? If you have booked direct from us, you could have saved  {BXSVCFEE} on your stay - that is the amount {BSOURCE} charged YOU for using their site. Sites like Homeaway/VRBO, AirBNB and TripAdvisor mark up owner's rates by anywhere from 7 to 17%! Find individual property websites (like ours) and social media pages and bypass paying excessive fees to a 3rd party middlemen. 

Please know that there are real people behind owning, caring for and maintaining vacation properties like ours, so you are not "renting an AirBnB" - you are renting someone's vacation home, 2nd home or future retirement dream home. These mega booking sites do not own vacation homes - folks like us do.

Returning guests do not need to overpay - get the best total price by booking direct with us (any of our cabins!) and we offer friends/family referral discount.

We are "social" - 'Like'{PDISPNAME} on  and follow on  - we post updates, photos, area info, specials, or availability due to last minute cancellations. We welcome you sharing photos of your vacation!

Thanks again, and if you have any questions or concerns, or need information, please let us know.