Is it worth doing it on the cheap way or shall we save money and come back later in our lives...??
As far as Galapagos, the majority of our clients come back saying that it was absolutely worth it, however, it is pricey.
There are cruises for 4, 5 & 8 days in a variety of different yachts, ranging from luxury to very basic (sometimes they don't even have hot water). I personally recommend the 8 day cruises as you get to see the southern & northern loop. The best thing would be to get you a last minute booking as the yachts drop their prices considerably. Just to give you an idea a last minute 8 day cruise would work out around $1200 per person, 5 days around $800 & 4 days around $500 - these prices include cruise, accommodation in a double occupancy cabin, all meals, guided treks & taxes.
Or you have the option of staying on Santa Cruz, Isabela or San Cristobal and taking daily tours to other islands. Daily tours work out around $100 - $150 per person per day or you can take a boat to the other main islands for around $30 per person. There are camping spots on Isabela and some budget hotels on Santa Cruz (around $20 p/ person - Margarita seems to think you may even find something cheaper hostels).
Flights work out at around $400 per person and on arrival at the Galapagos Islands you must pay an entry fee of $100 per person.
I'm enclosing a link to other places that may be of interest to you here in Ecuador that are not as pricey, we may be able to find cheaper tours than the ones advertised on our site. Ecuador Adventures
Anyway I hope this information helps and if you have any further questions about Galapagos or any other destinations here in Ecuador, please don't hesitate to contact me.