Firstly, it's expensive, and secondly, it's too slow.是什么意思？

Firstly, it's expensive, and secondly, it's too slow.

首先是价格贵，其次，速度太慢。

firstly

adv. 第一，首先（主要用于列举条目、论点时）；

例句
The programme is now seven years behind schedule as a result, firstly of increased costs, then of technical problems...
该项目现已经比预定时间晚了7年，原因首先是因为成本增加，其次是由于技术问题。

expensive

adj. 昂贵的，花钱多的，豪华的；

例句
I spend a lot on expensive jewelry and clothing...
我花很多钱购买昂贵的首饰和衣服。

and

conj. 和，与，而且，于是，然后，因此；

例句
I spend a lot on expensive jewelry and clothing...
我花很多钱购买昂贵的首饰和衣服。

secondly

adv. 第二，其次；

例句
The amount of secondly ettringite is affected by the curing condition.
二次钙矾石的形成量受养护条件的影响.

too

adv. 也，太，很，非常；

例句
The steep pavement was too narrow for them to walk abreast.
陡坡太窄，他们没法并排走。

slow

adj. 慢的，迟钝的，温和的，慢于…的；adv. 慢慢地，缓慢地；vt.& vi. （使）缓行，（使）减速；vi. 变慢，变萧条；vt. 放慢，阻碍；

例句
It's not a job for anyone who is slow with numbers...
这份工作不适合不擅长算术的人。