I visited Vietnam some years ago and the cruise line organised the visas on board (you were provided all the forms on boarding the ship) and the cost was included in the cruise. The country is a bit more open now so I don't know the latest situation but initially I would check direct with Costa and also await more replies on this board as I'm sure many people have been more recently. I can't help you with regard to China.
I had to apply for visa's for going into Australia and they each cost around £20, so price sounds fair. There is no way you can get these on the ship, if you arrive at the airport at check-in they will be asking if you have visa's so you need them before you go or you won't get on the plane. If you are still unhappy ask your travel agent if they can suggest an alternative source.
I dont know about Vietnam but I have recently been to China and the visa costs £30 and I had to go to the Consulate in Manchester to get it. A bit of hassle as they are being very strict due to Olympics. Might be easier to let them get it for you.
A tourist visa for china is £30 and vietnam is £38 plus £7 postage. Use google to search as I have done. "Best option" is to leave it to the experts, which in this case are the cruise line. The cost seems resonable bearing in mind the visa costs and the fact that you will not have to do the leg work !!!
I dealt with Coast Cruise directly when booking the same cruise. They will organise your VISA's and charge to your onboard account. 4.50 Euro for Vietnam and included in cost of excursion in Sanya China else it will be 20 Euro each. Don't go handing £100 to TA for visas.
We are also going to China and Vietnam in November. We are going on Princess and have been told we will get our Vietnamese visa on board and cost charged to our account. We need a double entry visa for China which costs £45 if you go to the embassy twice. We however went through 5 star chinese Visa Company who charged us only an additional £20 (far, far less than the offer from Princess and our travel company) and the service was excellent. We made an appointment through their web site for Monday - posted our application to them to arrive the previous Friday and had everything back on the Friday. Instructions are clear on the web site and there has always been someone answering the phone if you need to clarify anything. Amazing for the money. Hope this helps.
Thanks for that - however our passports, visa forms and balance due to tour company have now been paid. Just awaiting return of passports and tickets etc. Looking forward to our 1st ever cruise. Hope you enjoy China & Vietnam .