Advice needed on $300 airline credit!!
Have this award itinerary on hold:

MIA-IAD-BOM*-JNB*-CPT*-LHR-MIA
*4 nights each;
busn except CPT-LHR-MIA econ;
67.5K+45K+37.5K = 150K AA miles + $396 total taxes-fees
($276 of that AA UK-fuel-fee)
hold good until 2/4 but...
by 2/3 $25 phone fee
starting 2/4 $75 phone + 21 day fee

How do I employ Ritz card to get some or all of my $300??
Buy multiple AA gift cards in advance?
Use those to pay $396 + $25-or-$75?
(itinerary: mostly Etihad, BA, AA)
What size? Any advice appreciated!!
Possible explanation, if asked:
"upgrading" to busn award on some segments = higher taxes/fees...?