out side landscaping maintenance

It is completely up to what you have to landscape.

DanaR:
Have you consulted landscapers to do a walk-thru and define exactly what you want them to do vs. what they tell you needs to be done? It is advisable to get at least 3 bids for the same work so you can compare apples to apples.
That way, you will have a better understanding of exactly how much you will need to include as part of the assessment fee per resident. I am assuming your covenant docs state that the association must assume responsibility for landscaping maintenance. This is always subjective, however, as to what level the association/community wants to take the 'responsibility', and above all, how much they are willing to pay for. It sounds like you may have spoken to a contractor already for you to believe you will require 5-7 man crew 5 days a week. This must be a HUGE AREA to maintain and one I'm not sure I would want to fund.

I believe there may be documents on this site that will speak to landscaping variables, totally manicured from every blade of grass/weeds/flowers to something less extensive. Its all up to how much the residents are willing to pay.

By the way, what type of community is yours that you actually collect fees of $150,000.00 per month?

You don't define the bid the landscapers do. Telling someone your willing to pay $30K a year will get you $30K a year for a job that might cost $25K on average.
What you need to do is shop around. Call atleast 3 - 5 landscapers and give them the SAME definition of the work to be completed. Make sure everyone agrees to the type and area the work is to be done. For example: Do you want them to clean around any dumpsters or cut branches back from any roadways? Some members may NOT want that. You have to go with what the majority of the members feel the defined work should be. A landscaper may try to "extend" or "limit" what they are willing to do without a definite definition.
I think it is a HUGE mistake to decide how much your (HOA) is willing to pay a contractor. Bids define themselves in most cases. Do some research. Ask another HOA what they get done and at what cost. Our HOA paid $2,100 a month for 12 months and the job is done only for 8 months a year. 4 months are winter type months where the grass is dormant and little maintenance is needed. We just couldn't afford to pay the contract in 8 month terms. Plus the contractor is on a yearly contract. That allowed them to get paid until the contract was up and be bound to come out throughout the "dormant" months for necessary touch-ups.
Make sure the contractor is licensed and insured for atleast a million dollars. Never do business with a contractor unless they are licensed and insured or possibly even bonded.

Wow Brad! An Agreement? I knew you would come my way one day! Anyway, it should be a policy or an agreement that there are 3 bids whenever the amount of work needed to be done is over say $100 or $500 depending on what one may consider a "large" job. Lawncare and Management companies take the largest amount of any HOA budget when it comes to contractors. Be careful in signing deals/contracts lasting more than one year terms.
Another issue, is be careful with VERBAL agreements. Apparently, the first board of our HOA 15 years ago told a lawncare contractor they had the contract for $40K a year but HIRED someone else. That other lawncare contractor sued the HOA for the terms of the contract. ($40k). I believe the lawncare contractor won. They NEVER cut a blade of grass in the HOA!

Dana:

Prepare a bid spec sheet and put it on paper everything you want each landscaper to bid on. This way each company is bidding apples to apples. Also include in your bid spec sheet that they supply you with their Insuance Certificate, naming the HOA on their Rider and make sure they have workmen's comp covering their employees.

List in detail what your HOA expects:

Spring clean up, cleaning all flower beds, weeding, trimming, mulch/pine needles, fertilzer, lime, arerating,over-seeding, turn on irrigation system, planting flowers...

You can see where I am going, any jobs (projects) that are being sought out should all have a bid spec sheet listing your requirments to the contractor as well as a bid deadline, so you can get them all in on-time.