What is the meaning of 'tight' and 'buck' etc.

[gonghoujun]

Dear Teacher,
I have read the sentences as follows:
This is particularly true when the decorator joins forces with the man's wife,who obviously knows more about furniture than her husband. Of course, she's interested in convincing her husband that he shouldn't be so tight with the buck,which automatically means that he has a two-on-one battle on his hands right from the start.
Explain them in detail, please:
1. the meaning of tight here.
2. buck=money, or man?
3. the meaning of two-on-one battle.
4. the meaning of on his hands here.
Thanks!

[Gillnetter]

Dear Teacher,
I have read the sentences as follows:
This is particularly true when the decorator joins forces with the man's wife,who obviously knows more about furniture than her husband. Of course, she's interested in convincing her husband that he shouldn't be so tight with the buck,which automatically means that he has a two-on-one battle on his hands right from the start.
Explain them in detail, please:
1. the meaning of tight here. Unwilling to spend money.
2. buck=money, or man? Money - dollars
3. the meaning of two-on-one battle. The wife and the decorator are working against the husband.
4. the meaning of on his hands here. Something he has to confront. Something he has to deal with and/or solve.
Thanks!

Gil

[gonghoujun]

After reading the kind/good reply of Teacher Gillnetter, I know the meaning of these words or phrases. Thank you!