Your Dentist might adviced you based on through examination...
Based on your age an concern (unable to eat) you will more likely to go to other diet related conditions as you are less likely to digest all the food you eat because of Bad teeth.
Did you ask your Dentist what was the reason for your gum problem ?
Most likely it is poor oral hygiene then any elaborate and costly alternatives will be bound to fail
Next Steps
counsel your self on what you want (teeth replacement) vs what you can afford (not based on cost but your ability to maintain prosthesis)
ask for the reason of your bad gums and discuss how you can overcome them
Health Tips
maintain Good Oral hygiene