Perhaps an example helps.
Suppose @RPietila is now in the US (to simplify the example) and wants to buy a bottle of fine French wine that costs 500$ if paid in cash at the store -- just the current market price of 1 BTC -- with free delivery to @RPietila's location. The wine merchant "accepts bitcoin" through Bitpay.
GOING THROUGH BITCOIN:
Years ago, when the price was 3$/BTC, all fees included, @Rpietila bought (say) 1.03 BTC for 3.09$
Today, @Rpietila clicks the bitcoin payment option and is directed to a Bitpay form that specifies the amount of bitcoin he must send, which is 1 BTC plus (say) 0.03 BTC to cover all the costs and fees.
@Rpietila transfers 1.03 BTC to the Bitpay address, shown on the form. Let's suppose there is no fee for that.
Bitpay sends 500$ to the wine merchant's bank account. Pays a bank transfer fee for that, let's say 5$.
Bitpay sends the 1.03 BTC to Bitstamp and puts it up for sale. Let's suppose there is no fee for that.
@JayJuanGee deposits 520$ into his Bitstamp account. Pays a bank transfer fee for that, let's say 5$.
@JayJuanGee buys the 1.03 BTC for 515$ (suppose that, by miracle, the price hasn't changed). Pays a trading fee on that, let's say another 5$.
@JayJuanGee withdraws the 1.03 BTC. Let's suppose there is no fee for that.
@Bitpay now has 515$ in its Bitstamp account. Withdraws 510$ to its bank account and pays a withdrawal/bank transfer fee of $5.
NET RESULT:
Bitpay paid 505$ (including one bank fee) and received 510$ (after all Bitstamp fees). The 5$ difference is their processing fee.
@RPietila paid 3.09$ and got to enjoy a bottle of fine wine worth 500$. He has the same amount of bitcoins that he would have if he did not buy those 1.03 BTC way then.
@JayJuanGee paid 525$ for the privilege of paying the rest of @Rpietila's wine bill (496.91$), plus three bank transfer fees, the Bitstamp trading fee, and the Bitpay processing fee; but he now has 1.03 BTC more in his hoard, nominally worth 515$, that he may be able to sell to @Erdogan tomorrow and thus pass that privilege on to him.
WITHOUT GOING THROUGH BITCOIN
@Rpietila clicks the bank payment option and gets the wine merchant's bank account #.
@RPietila sends 500$ to that account, pays a bank transfer fee of 5$.
NET RESULT:
@RPietila paid 505$ and got to enjoy a bottle of fine wine worth 500$.
CONCLUSION: Left as an exercise.
Yeah... attempt to get us to bite, by using our names.... O.k.... fine.. I will bite a little bit... while kicking and screaming somewhat with the hypothetical.
I don't like homework and I do NOT own a Bitstamp account.
Further, each of us calculates his/her spending behavior based on the options available, and that may NOT always be determined by BTC price alone, or transaction fees or whether we feel that someone else is profiting from us.. but also based on convenience and ideology ... and in the case of bitcoin that we may be also using it as a storage of wealth.
Currently, I continue to buy and hold and to use BTC as a storage of wealth.
I could give a flying fuck, if some earlier adopter, whether Rpietilla or any other earlier adopter, had bought at a cheaper price than me and is potentially profiting off my buying of BTC at a greater price. If I buy BTC, then I buy at the going market rate or I attempt to time my purchase on a price dip, and I engage in this behavior based on my own individual calculations of my best interest.
These days, since my BTC portfolio is in the red, if I use BTC to purchase any kind of item, I immediately replace that BTC with additional BTC purchases.
All your various numbers in your hypothetical are quasi-irrelevant because each person is going to calculate his/her behavior based on the options available to him/her and the goals s/he is attempting to achieve... and sometimes the calculations are going to change based on prices available and whether his/her portfolio is in the red or black and by how much.