Hey !
Coming back go this forum after a long time. Loans from bike shop can really cut you up to 6 to 8% high. Plus got got a lot of "fees" like admin fee, termination fee, drink kopi fee.
These fees can otherwise can be used towards paying for your bike but instead its "wasted" on these extra expenses. So rule of thumb will always be to save up as much as you can so most of your money is going to the bikes.
But we are not rich but the heart does not listen so how? .. next option is actually to go for personal loan from a bank. This is because the you control the terms and if you manage to get bonus or strike 4d you can pay off the loan and save money. If no choice have to go to bike shop try to go to those with no termination fee. Will make your life much easier when you are trading up.
Can recommend Loois, the bikes and services may be slightly higher than the norm but you know you will always be supported should something happen to your bike.
As for upgrading to 2A... the moment you sign the loan contract your ass belongs to the bank/bike shop until the value of the bike can pay for itself/ release you from your loan.
EG:
2020 CB150R
D/P 500
Loan 14000
Interest per annum 6%
No of years 3 yrs ( Since you want to upgrade to 2A/2)
Total Interest = 3x6 = 18%
Loan Ammount = 14000 + [18/100 *14000] = 16250
Installment = 16250 / 36 ~ 459.
So lets say you pay for 12 mth and want to upgrade because you pass your 2A
12*459 = 5508.
Remaining Loan = 10,742.
You cant get rid of your bike unless you pay off 10,742. But if your bike value is equal or more than this amount, you maybe able to trade in.
My suggestion would be to skip 2A and keep the 2B bike for till you change to class 2 and save up for your class 2 bike along the way. May seem a long way but when the day finally arrives, its the best feeling ever. =) All the best!