Thanks for restarting this discussion.
First of all, I really like flippa as an auction place, it looks great, feel great and works great.
Now coming to the topic,
The Gist of what I have learnt from past experiences, if you have a great domain name, then a flippa premium upgrade of $250 or above would help, otherwise it would be too risky to buy individual upgrade. If you have free credits, that is another thing. You can request for concessions as well.
The matter of fact is that, the full upgrade allows you to show case your domain as a premium one, with logo & everything else as a complete package. This would help not let your domain auction buried in the junk domain auctions at flippa & who knows some investor might like your domain.
However, just dont forget to take another opinion here at namepros appraisal section, or from domain help team at flippa, whether they think a full upgrade may work for your domain or not, but I am sure no one can guarantee anything, it is on us to decide finally.
For Selecting from individual options.
It would only help if you really have a great name, but first list your domain without having an individual upgrade to see the response & watchers. Promote it for free here at namepros external auction page. Since the re-listing is free you can re-list your domain several times like for instance 3-4 days auction or 14 days auction & in that way you would be able to get an idea about the response it may generate.
Secondly, you can contact flippa domain help at their ID, they may tell you what they think about your domain name, but I am not sure, only get to know this from recent interview of flippa domains director
@FlippaDomains
A Must Read Interview with Kevin Fink on all things Flippa
Feel free to get in touch with domain help team, they can help you positively I am sure.
These are the options to select from upgrades:
1. If you have some free credits available & a really good domain name, the flippa home page featured listing of $49 can help getting some watchers.
2. Regarding flippa email & tweet upgrade option thing I am not sure it would help that much as the flippa homepage feature, just my opinion, anyone can differ as per their experience. It may depend on your domain name, and timing of auction, pre-auction exposure, your credibility and feedbacks at flippa, your past sales and so many other things. Your Domain name Watchers at flippa, you may like to list your flippa username here:
What is Your Flippa Username
3. Bold listing & highlighted background are also great features with low cost, you may use free credits if you have.
4. For spot light listing, I think they only offer it if any space is available, and that too if you have already taken a minimum upgrade of $149 (correct me if I am wrong), or who knows they may give you on request, simply email them before auction.
This was just an opinion, more thoughtful notes by other members will be highly appreciable on flippa premium upgrades and a choice of availing individual flippa upgrade options.
@FlippaDomains may would like to comment and give an advice/suggestion/recommendation here.