sou da japanese grammar

This is an given example but without a translation so I would like if I get the correct meaning.
1)この店は高くて美味しくなさそうだから、隣の店にしよう。
- Since the store is expensive and not tasty, let's go to the next store. (美味しくなさ-tasty or not tasty)

Is the sentence below made up with the correct grammar structure?
2)この鞄を見てから、買いたさそうだ?

You should avoid systematically translating 美味しい as "tasty" (or "delicious") as many Japanese do. "Tasty" usually results in unnatural English; most people just say "good".

For the first one, you don't actually know how good the food is if you haven't tried it, which is why 〜そう is used, to mean something like "it's expensive and it doesn't look too good, so let's look for another one".

For 2 I'm not sure what you're trying to say.

Hi!
My English is not good but let me answer your question.
Firstly, "〜そうだ" is used when you don't have any experience about what you talk.
If you have some experience about that, you will say: this restaurant "is" too expensive and food in there is not good, so let's go to the next one.
The other hand, if you don't have any experience about the restaurant which you talk about at first, you will say:this restaurant seems to be too expensive and food would be not good, so let's go the next one.
That is the difference!
In short, "〜そうだ" equal "it seems" or "it sounds" . Because you just look or see and think about it without any experience.

Let's see the second sentence you wrote.
この鞄を見てから、買いたさそうだ
I guess you want to say in English:I see this bag and want to buy it.
If my guessing is right, let it be in Japanese.
この鞄を見たら買いたくなった

If you want to use "〜そうだ", it's okey when you think something about that bag but you don't have any experience and true details. Or you just look and guess someone think something but you don't really know the truth.
For example, あの人はこの鞄を買いたさそうだ.
meaning in English:that man seems to buy this bag.
In this case, you just look at someone and he seems to buy the bag but you don't know he really think so.

One more example. The case when you want to think about the bag, not the others.
この鞄は使いやすそうだ
It can use when you see the bag and think it is useful. In short, you have never used the bag but it seems to be useful.

I wish I could help with your learning.

Thank you very much for both of your responses.
@Lisnoir
For the sentence below, should it be 使いやすさそうだ　or 使いやすそうだ (Is this the shorter version?)
この鞄は使いやすそうだ.

According to the grammar point, い should be converted to さ.

For the sentence below, should it be 使いやすさそうだ　or 使いやすそうだ (Is this the shorter version?)

Actually these are two different forms. Normally language books explain the difference or you can also ask your teacher. But essentially 使いやすいそうだ means that you “heard/read” that is is easy to use. There is some objective information from someone else telling you that.
While with the other form you just GUESSthat it’s easy to use. Eg Because you see a 4 yr old using it. But you don’t know anything else. Maybe she has been training on it for 4 yrs and for everyone else it’s hard to use.