Expressing the concept of "instead"

Question

I'd have liked to have asked this as a comment to the accepted answer in the post linked below but sadly, my reputation does not yet allow that.

in 買っては, I need some explanation for っては part

In the above post, the sentence

靴買うならTシャツやいま使うもの買っては？！

is translated as

"If you're going to buy shoes, how about buying / why don't you buy a t-shirt / t-shirts or an item / items that you'll use now instead (rather than shoes)?"

I was wondering why the translator is so confident that "instead" is implied rather than "as well". When I hear "How about..." in English, I feel at best a slight implication of "instead of the alternative". Does "どうですか" carry a strong implication of "instead" in Japanese?

Further, is there a way that the speaker could have emphasized her meaning with a specific word or expression (something like "rather than the alternatives")?

And lastly, how could the speaker have have said:

"If you're going to buy shoes, how about buying / why don't you buy a t-shirt / t-shirts or an item / items that you'll use now as well?"

Thanks all for reading. Any help is appreciated.

Answer 1

This 'instead' was kindly inserted by the translator because the speaker did not use も (=also, as well) in the original sentence. It's the absence of も that implies the speaker is suggesting buying something else instead.

• 靴(を)買うならTシャツも買っては？
  If you're going to buy shoes, why don't you buy a T-shirt as well?
• 靴(を)買うならTシャツ(を)買っては？
  If you're going to buy shoes, why don't you buy a T-shirt (instead)?

And this answered your last question, too.