Good afternoon,
I have an interest in purchasing a support package of the lower tiers right now, but I would like to at least purchase the $250 pack later on.
My question is will can I purchase a $10 package and upgrade to a higher tier later?
Thank you for the input, in advance.
I am sure Sarno will get back to you on the specifics later. But just to let you know now that upgrades are definitely possible 
The alpha packs will be available for quite a while - over half a year - and you can either purchase or upgrade to any of them while they are available. This won’t be possible after they have left the store, regardless of whether you’ve purchased one or not. Please let me know if you have any other questions.
Thank you for the responses.
I am glad that I can upgrade my packages so I can properly budget and purchase the tier that I would like.
If we bought the game through steam, will we be able to upgrade our supporter pack, or do we have to buy it separately?
You can raise a support ticket to upgrade an existing pack to a higher one & pay the difference, but unfortunately they aren’t doing that at the moment (& haven’t for quite a long time).