Here's my best attempt at the total recent-ish fees for MD1-4 (I don't know what happens when you get to 5), please correct me if I'm wrong. This includes all the 'hidden' fees which I can think of and I've separated it into different sections depending on whether or not you get school housing. This is split into multiple calculations depending on whether you get your own housing or school housing and the cost of that housing.

$3990 tuition per semester
$180 Activity registration fee
$150 bus fee (optional but most MD1s will want this)
$100 medical insurance fee
$200 hurricane fee
$50/exam for each NBME exam fee (let's say an average of 4 NBME exams per semester making it $200 per semester)

+$150 Visa fee (this is separate from the school invoice fees since it's paid separately with the Visa application once you get to the island and apply for Visa)
+$300 refundable book fee (this is also separate from the regular tuition charges since it's optional and paid when you first get your books)

Plus school housing fees excluding rent
$1000 charge for each semester with school housing
$500 dorm surcharge ($125/month)
$500 refundable security deposit
=$7120 when adding to the amount above

Rent with variation (if you live on school housing then you have to pay rent on top of the fees above. This might also include an electricity overcharge at certain locations - the three atm are Royal/Bird Rock/Sugar Bay. Since most NAmerican students who use school housing use Royal/Sugar Bay, the rent per month is around $530-900ish depending on your room and assuming you use a single non-shared room)
+minimum $530 and max $900, I'll use the average of $750 x 4 months so adding to the number above:

$10120 on average total for MD1 for school tuition/fees/school housing average at Sugar Bay or Royal. For MD 2-4, subtract $150 for Visa, $300 for books, and $500 for housing security deposit since you only pay these fees in MD 1 so it would be $9170 for MD 2-4 all with school housing.

Calculation for semester payment without school housing for MD1 (if you live without school housing and all the involved surcharges for school housing then the total semester payment is the following depending on your monthly rent):
-Using initial $5120 (number for MD1 fees above without housing fees) + 4 x monthly rent = $7520 if rent is $600/month; $7920 if rent is $700/month; $8320 if rent is $800/month. Note that you may have hydro/internet charges but a lot of places don't.
-Using $4670 (number for MD2-4 fees without housing from above) + 4 x monthly rent = $7070 if rent is $600/month; $7470 if rent is $700/month; $7870 if rent is $800/month.

The total payment is significantly less if you get your own housing rather than the school provided housing and even cheaper if you get a roommate (I didn't show the roommate numbers above but you can cut your rent payments in half if you use a roomate at school or private housing). Obviously you'll have to budget in food/living expenses/plane tickets and possibly a cost or anything else for additional expenses but this should give an idea of what I'd call the mandatory tuition related charges as well as housing whether private or personal. Hopefully an MD5+ can give us an idea of later charges.