The issue with these perks is that there is a relatively limited amount of total affection each character will get during their career, the perks do NOT apply across your entire legacy, and each point of affection can be assigned a value in credits based on the cost of gifts. Paying a large number of credits for an exp bonus that cannot be earned any other way - thus saving you time in leveling - is a luxury item. Paying a large amount of credits for an affection bonus when you could have just purchased enough gifts to get that much affection for a smaller amount of credits is just bad planning.
Anyway, in response Bioware tweaked the numbers - the bonus has been doubled and the cost slashed by 2.5-fold. The good news is that the entry level perks are a very attractive deal, especially for newer characters. (The deal gets worse as you complete more of the story, because you will have fewer remaining quests to benefit from the bonus.) At 10K each for 10% bonuses to gifts and conversation gains, I'm not going to spend too long worrying about whether I got the best deal.
Unfortunately, I'm still not convinced about the higher ranks. It's an extra 30K credits (per bonus) for an additional 10% affection, but my guess is that you will most likely cap out your affection with most or all of your companions before you really benefit from this increase. I guess the real question is whether +20% to conversations would allow you to slash or eliminate your gift budget - you will definitely profit from a single rank of the gift perk if you're handing out rank 1 gifts until they stop awarding points, but this will still cost you some money (roughly 30K credits per companion for the non-picky companions). Then again, the numbers are probably close enough that it doesn't really matter.
If you're curious, here's an update to my numbers on how much you can save on rank 1 and 2 vendor gifts with the 10% bonus.
|Affection Range||Affection/Gift||Total Gifts|
|0-1999 (base)||96||21 (to 2016)|
|0-1999 (+10%)||105.6||19 (to 2006.4)|
|2000-3999 (base)||48||42 (from 2016 to 4032)|
|2000-3999 (+10%)||52.8||38 (from 2016 to 4012.8)|
|4000-5999 (base)||19||104 (from 4032 to 6008)|
|4000-5999 (+10%)||20.9||96 (from 4012.8 to 6019.2)|
|6000-7999 (base - rank 2 gifts)||19||105 (from 6008 to 8003)|
|6000-7999 (+10% - rank 2 gifts)||20.9||95 (from 6019.2 to 8004.7)|