I would highly recommend you NOT use Smile Direct or any cut rate system.
#1 There will be no direct supervision of your case during treatment ( you should be seen by a trained a qualified dentist every 6 weeks or so.) and
#2 No one will consider or monitor your periodontal health or anything else about your dental health which could adversely effect the longevity and long term stability of your teeth.
#3. Smile direct uses NO attachments on your teeth which are needed for many of the movements required to properly align and rotate teeth.
#4 Align/ Invisalign has hundreds of Patents on their technology which has been constantly been improving for 22 years. which Smile Direct does not have.
#5 MOST IMPORTANTLY – Without constant supervision of your case you may end up wth a resulting dental health problem you did not expect or desire.
Also my advice is go to a Cosmetic general dentist who is experienced and qualified Invisalign provider,. There are financing options at zero interest and in the long run I believe you will find the best care is the least expensive.