A serger and a sewing machine are two different things. You can find some decent sergers for less than 300.00. All brands is a good place. The serger and the portable machine she uses would most likely meet her needs.

On a personal note, I like picking out my own machines. You don't want me picking out your lawn mower, drill, leaf blower, chain saw,pressure washer, etc. Give her a "gift certificate" for a set amt. that she can apply to a new machine.
Good Luck,
Susan

A serger is also sometimes called an overlocker or an overlock machine. They do not have bobbins and sew with 2, 3, 4, or 5 threads, and 1, 2, or 3 needles depending on the selected stitch style.

They include a set of knives that cuts off the extra seam allownance and the seam is enclosed in threads. Sergers have been used in industrial sewing for more than 100 years, but the first successful home sergers came on the market in about 1960.

A serger can make a number of sewing tasks much easier and faster, and provide a nicer finish. You still need a regular sewing machine; a serger can't do everything.

At the bottom of this post is a link to a very nice guide on selecting a serger (from the Mississippi State University Extension Service) with a handy checklist for comparing features.

Susan is quite right when she notes that you can get a very decent serger for less than $300.

CMC

Here is a link that might be useful: Serger Selection guide

What you could do is give her a gift certificate to your local sewing machine store or take her there and let her pick out the one she wants. You have to try these things out before you buy them to see which one you are most comfortable using. I would go for the serger since she already has a portable sewing machine. Colleen

YES I agree gift certificate let her pick out what she wants. YOU might ask her if she has a favorite brand tho as not all stores carry all brands.

Have a talk with her best girlfriend. Prompt her to ask your wife about what she wants fro her birthday. It's kinda sneaky but your wife will be the winner here!
Salena

Take her out to lunch and then let her pick out the machine she wants. A good store will let her try machines to her hearts content -- and she'll have some great stories to tell her friends about her wonderful husband.

I work in a fabric/sewing machine store. Today a lady came in and traded her never-used, high-end machine that her hubby bought her. The gift machine wasn't the brand she preferred, so she bought a new one from us. We have gift cards, and I would advise a husband to do that rather than select something on her behalf, or better yet have her come and test drive machines as some here have already suggested.

Mary